scholarly journals Queing Theory, a Tool for Polio Eradication in Nigeria

2021 ◽  
pp. 123-133
Author(s):  
Raphael Ayan Adeleke ◽  
Ibrahim Ismaila Itopa ◽  
Sule Omeiza Bashiru
Keyword(s):  
Polio Eradication ◽  
Arrival Process ◽  
Health Departments ◽  
Batch Arrivals ◽  
Parallel Servers ◽  
Contagious Diseases ◽  
Poisson Arrival ◽  
Self Service ◽  
Using Data ◽  
Set Up

To curb the spread of contagious diseases and the recent polio outbreak in Nigeria, health departments must set up and operate clinics to dispense medications or vaccines. Residents arrive according to an external (not necessarily Poisson) Arrival process to the clinic. When a resident arrives, he goes to the first workstation, based on his or her information, the resident moves from one workstation to another in the clinic. The queuing network is decomposed by estimating the performance of each workstation using a combination of exact and approximate models. A key contribution of this research is to introduce approximations for workstations with batch arrivals and multiple parallel servers, for workstations with batch service processes and multiple parallel servers, and for self service workstations. We validated the models for likely scenarios using data collected from one of the states vaccination clinics in the country during the vaccination exercises.

scholarly journals An Erlang Loss Queue with Time-Phased Batch Arrivals as a Model for Traffic Control in Communication Networks

2008 ◽  
Vol 2008 ◽  
pp. 1-14
Author(s):  
Moon Ho Lee ◽  
Sergey A. Dudin
Keyword(s):  
Communication Networks ◽  
Traffic Control ◽  
Batch Arrival ◽  
Arrival Process ◽  
Batch Arrivals ◽  
Poisson Arrival ◽  
Batch Arrival Of Customers ◽  
Single Epoch ◽  
Erlang Loss ◽  
Arbitrary Flow

A multiserver queueing model that does not have a buffer but has batch arrival of customers is considered. In contrast to the standard batch arrival, in which the entire batch arrives at the system during a single epoch, we assume that the customers of a batch (flow) arrive individually in exponentially distributed times. The service time is exponentially distributed. Flows arrive according to a stationary Poisson arrival process. The flow size distribution is geometric. The number of flows that can be simultaneously admitted to the system is under control. The loss of any customer from an admitted flow, with a fixed probability, implies termination of the flow arrival. Analysis of the sojourn time and loss probability of an arbitrary flow is performed.

scholarly journals Integration of various scales for measurement of insomnia

2021 ◽  
pp. 263208432110100
Author(s):  
Satyendra Nath Chakrabartty
Keyword(s):  
Test Scores ◽  
Data Driven ◽  
Weighted Sum ◽  
Future Studies ◽  
Normal Probability ◽  
Equivalent Test ◽  
Item Scores ◽  
Using Data ◽  
Set Up ◽  
Different Levels

Background Scales for evaluating insomnia differ in number of items, response format, and result in different scores distributions and score ranges and may not facilitate meaningful comparisons. Objectives Transform ordinal item-scores of three scales of insomnia to continuous, equidistant, monotonic, normally distributed scores, avoiding limitations of summative scoring of Likert scales. Methods Equidistant item-scores by weighted sum using data-driven weights to different levels of different items, considering cell frequencies of Item-Levels matrix, followed by normalization and conversion to [1, 10]. Equivalent test-scores (as sum of transformed item- scores) for a pair of scales were found by Normal Probability curves. Empirical illustration given. Results Transformed test-scores are continuous, monotonic and followed Normal distribution with no outliers and tied scores. Such test-scores facilitate ranking, better classification and meaningful comparison of scales of different lengths and formats and finding equivalent score combinations of two scales. For a given value of transformed test-score of a scale, easy alternate method avoiding integration proposed to find equivalent scores of another scales. Equivalent scores of scales help to relate various cut-off scores of different scales and uniformity in interpretations. Integration of various scales of insomnia is achieved by finding one-to-one correspondence among the equivalent score of various scales with correlation over 0.99 Conclusion Resultant test-scores facilitated undertaking analysis in parametric set up. Considering the theoretical advantages including meaningfulness of operations, better comparison, use of such method of transforming scores of Likert items/test is recommended test and items, Future studies were suggested.

scholarly journals Transient and Stationary Losses in a Finite-Buffer Queue with Batch Arrivals

2012 ◽  
Vol 2012 ◽  
pp. 1-17 ◽  
Author(s):  
Andrzej Chydzinski ◽  
Blazej Adamczyk
Keyword(s):  
Batch Size ◽  
Buffer Size ◽  
Arrival Process ◽  
Time Interval ◽  
Finite Buffer ◽  
Finite Time Interval ◽  
Batch Arrivals ◽  
Batch Markovian Arrival Process ◽  
Buffer Overflows ◽  
Finite Buffer Queue

We present an analysis of the number of losses, caused by the buffer overflows, in a finite-buffer queue with batch arrivals and autocorrelated interarrival times. Using the batch Markovian arrival process, the formulas for the average number of losses in a finite time interval and the stationary loss ratio are shown. In addition, several numerical examples are presented, including illustrations of the dependence of the number of losses on the average batch size, buffer size, system load, autocorrelation structure, and time.

scholarly journals A Webgis Framework for Disseminating Processed Remotely Sensed on Land Cover Transformations

2016 ◽  
Vol 100 (1) ◽  
pp. 27-38 ◽  
Author(s):  
Grazia Caradonna ◽  
Antonio Novelli ◽  
Eufemia Tarantino ◽  
Raffaela Cefalo ◽  
Umberto Fratino
Keyword(s):  
Land Cover ◽  
Satellite Data ◽  
Vegetation Indices ◽  
Remote Sensing Data ◽  
Geospatial Data ◽  
Usage Patterns ◽  
Mediterranean Regions ◽  
Multi Temporal ◽  
Using Data ◽  
Set Up

Abstract Mediterranean regions have experienced significant soil degradation over the past decades. In this context, careful land observation using satellite data is crucial for understanding the long-term usage patterns of natural resources and facilitating their sustainable management to monitor and evaluate the potential degradation. Given the environmental and political interest on this problem, there is urgent need for a centralized repository and mechanism to share geospatial data, information and maps of land change. Geospatial data collecting is one of the most important task for many users because there are significant barriers in accessing and using data. This limit could be overcome by implementing a WebGIS through a combination of existing free and open source software for geographic information systems (FOSS4G). In this paper we preliminary discuss methods for collecting raster data in a geodatabase by processing open multi-temporal and multi-scale satellite data aimed at retrieving indicators for land degradation phenomenon (i.e. land cover/land use analysis, vegetation indices, trend analysis, etc.). Then we describe a methodology for designing a WebGIS framework in order to disseminate information through maps for territory monitoring. Basic WebGIS functions were extended with the help of POSTGIS database and OpenLayers libraries. Geoserver was customized to set up and enhance the website functions developing various advanced queries using PostgreSQL and innovative tools to carry out efficiently multi-layer overlay analysis. The end-product is a simple system that provides the opportunity not only to consult interactively but also download processed remote sensing data.

scholarly journals Buruli-Ulcer Induced Disability in Ghana: A Study at Apromase in the Ashanti Region

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Pius Agbenorku ◽  
Anthony Edusei ◽  
Margaret Agbenorku ◽  
Thomas Diby ◽  
Esenam Nyador ◽  
...  
Keyword(s):  
Retrospective Study ◽  
Buruli Ulcer ◽  
Lower Limbs ◽  
Daily Activities ◽  
Ulcer Disease ◽  
Mission Hospital ◽  
Ankle Joints ◽  
Proportional Increase ◽  
Using Data ◽  
Set Up

Objectives. To describe trends and category of disabilities caused by Buruli ulcer disease. Design. This retrospective study was set up to quantify information on the disability trends caused by Buruli ulcer (BU) using data on patients attending BU and chronic ulcer clinics from 2004 to 2009, at Global Evangelical Mission Hospital, Apromase. Methods. Data was retrieved from the WHO BU1 form, case registry book, surgical theatre register, and BU patients' records book of the hospital. Disability was measured as the incapability of patients to perform one or more daily activities due to his/her state of BU disease before treatment. Results. A total of 336 positive BU cases comprising 181 males (53.9%) were recorded of which 113 (33.6%) cases of disabilities were identified. A mean age of 52.5 (±1.32) years was recorded. For the trend of disabilities, the year 2009 recorded the highest (N = 34, 31.0%). The lesions were mostly located at the lower limbs (N = 65, 57.5%) region of the patients. Lesions with diameter >15 cm were the major (59.3%) category of lesions. Conclusion. Trend of disability reveals proportional increase over the years from 2004 to 2009. Contracture at the knee and ankle joints was the commonest disability recorded.

scholarly journals Mapping gaseous amines, ammonia, and their particulate counterparts in marine atmospheres of China’s marginal seas: Part 1 – Differentiating marine emission from continental transport

2021 ◽  
Author(s):  
Dihui Chen ◽  
Yanjie Shen ◽  
Juntao Wang ◽  
Yang Gao ◽  
Huiwang Gao ◽  
...  
Keyword(s):  
Significant Negative Correlation ◽  
The Yellow Sea ◽  
Sea Spray ◽  
Marine Atmosphere ◽  
Coastal Site ◽  
Marginal Seas ◽  
Range Transport ◽  
Order Of Magnitude ◽  
Using Data ◽  
Set Up

Abstract. To study sea-derived gaseous amines, ammonia, and primary particulate aminium ions in the marine atmospheres of China's marginal seas, an onboard URG-9000D Ambient Ion Monitor-Ion chromatography (AIM-IC, Thermo Fisher) was set up on the front deck of the R/V Dongfanghong 3 to semi-continuously measure the spatiotemporal variations in the concentrations of atmospheric trimethylamine (TMAgas), dimethylamine (DMAgas), and ammonia (NH3gas) along with their particulate matter (PM2.5) counterparts. In this study, we differentiated marine emissions of the gas species originating from continental transport using data obtained from December 9 to 22, 2019 during the cruise over the Yellow and Bohai Seas, facilitated by additional measurements collected at a coastal site near the Yellow Sea during summer 2019. The data obtained during the cruise and the coastal site demonstrated that the observed TMAgas and protonated trimethylamine (TMAH+) in PM2.5 over the Yellow and Bohai Seas overwhelmingly originated from marine sources. During the cruise, there was no significant correlation (P > 0.05) between the simultaneously measured TMAH+ and TMAgas concentrations. Additionally, the concentrations of TMAH+ in the marine atmosphere varied around 0.28 ± 0.18 μg m−3 (average  ±  standard deviation), with several episodic hourly average values exceeding 1 μg m−3, which were approximately one order of magnitude larger than those of TMAgas (approximately 0.031 ± 0.009 μg m−3). Moreover, there was a significant negative correlation (P < 0.01) between the concentrations of TMAH+ and NH4+ in PM2.5 during the cruise. Therefore, the observed TMAH+ in PM2.5 was overwhelmingly derived from primary sea-spray aerosols. Using the TMAgas and TMAH+ in PM2.5 as tracers for sea-derived basic gases and sea-spray particulate aminium ions, the values of non-sea-derived DMAgas and NH3gas, as well as non-sea-spray particulate DMAH+ in PM2.5, were estimated, and the estimated average values of each species contributed to 16 %, 34 %, and 65 % of the observed average concentrations, respectively. Uncertainties remained in the estimations as TMAH+ may decompose into smaller molecules in seawater to varying extents. The non-sea-derived gases and non-sea-spray particulate DMAH+ likely originated from long-range transport from the upwind continents, according to the recorded offshore winds and increased concentrations of SO42− and NH4+ in PM2.5. The lack of a detectable increase in the particulate DMAH+, NH4+, and SO42− concentrations in several SO2 plumes did not support the secondary formation of particulate DMAH+ in the marine atmosphere.

scholarly journals An examination of linkages between corporate social responsibility and firm performance: Evidence from Moroccan listed firms

2021 ◽  
pp. 636-646
Author(s):  
Souhaila Kammoun ◽  
Youssra Ben Romdhane ◽  
Sahar Loukil ◽  
Abdelmajid Ibenrissoul
Keyword(s):  
Corporate Social Responsibility ◽  
Firm Performance ◽  
Social Responsibility ◽  
Positive Association ◽  
Social Enterprises ◽  
Listed Firms ◽  
Managerial Implications ◽  
Using Data ◽  
Set Up ◽  
Corporate Social

This article analyzes the complexity of the linkages between corporate social responsibility (CSR) and firm performance in Morocco and to decompose this complexity through a bidirectional sense of causality. Using data surveyed from 74 Moroccan listed firms, we conduct an econometric modeling to measure this relationship bilaterally and to investigate the underlying factors behind this association. The empirical study proves the existence of a positive association between CSR and firm performance in both directions in the Moroccan context and suggests that the more social enterprises are, the more they achieve better financial results. The mutual linkage between social and financial aspects allows us to draw some managerial implications and set up further research directions.

scholarly journals Beds, budgets and burdens: Learning disability expenditure v. workload across English health authorities

2002 ◽  
Vol 181 (3) ◽  
pp. 200-207 ◽  
Author(s):  
Bunny Forsyth ◽  
Paul Winterbottom
Keyword(s):  
Learning Disabilities ◽  
Learning Disability ◽  
Social Services ◽  
Rural Areas ◽  
Population Distribution ◽  
National Database ◽  
Health Authorities ◽  
Audit Commission ◽  
Using Data ◽  
Set Up

BackgroundFollowing the closure of asylums and widespread changes in the population distribution of people with learning disabilities, there has been little investigation of changing expenditure requirements of health authorities in England.AimsTo compare expenditure on learning disability health services across England with the burden of services regionally, as estimated by numbers of people with learning disabilities.MethodA national database was set up using data from the National Audit Commission and the Department of Health. The spend/burden ratio was calculated and correlation tests for likely causes of inequality were applied.ResultsThere is widespread discrepancy from the median spend/burden ratio of £10 260 per person with learning disability. There is a positive correlation between ratios and levels of net exports of people funded by their local authority social services to reside ‘out of area’. Comparative underspending occurs in rural areas.ConclusionsThere are inequalities in levels of spending on learning disability services. Comparison of regions suggests resources may not be allocated fairly. Health authorities should ensure that population increases are mirrored by appropriate adjustments in expenditure.

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